5) Wei-Yin Chen vs. Aaron Cook

Greg Fiume/Getty Images

The Baltimore Orioles have had a surprising amount of success this season and it has been in large part because of the performance of Wei-Yin Chen during his first year in the major leagues. Chen leads the Orioles starters with 12 wins.

On September 29, Chen squares off against Aaron Cook and the Boston Red Sox. While Cook is having a rough year, the importance of this game means that the Orioles need a dazzling start out of Chen as they look to clinch a playoff berth.

4) Clayton Kershaw vs. Tyler Chatwood

Jamie Sabau/Getty Images

Getting Clayton Kershaw back from his hip injury was huge for the Los Angeles Dodgers. They are trying to grab the final wild-card spot in the National League and they will need Kershaw to be on his game.

Squaring off against Kershaw on September 29th is Tyler Chatwood. Even though Chatwood has struggled this year, he is still capable of putting together a great game. The 22-year-old was rated as the 76th best prospect in the MLB prior to the 2011 season, according to Baseball America (via Baseball-Reference).

3) Jarrod Parker vs. Martin Perez

Mike Stobe/Getty Images

Two young starting pitchers will be facing off in one of the biggest series left this year. The Oakland Athletics will be playing the division-leading Texas Rangers as they try to hold onto their wild-card spot.

Jarrod Parker has been outstanding this season and has a 3.40 ERA. Martin Perez is just 21 years old and has been one of Baseball America's Top 100 prospects for the past four seasons (via Baseball-Reference).

2) Jered Weaver vs. Ryan Dempster

Stephen Dunn/Getty Images

The Los Angeles Angels and Texas Rangers series starts with an outstanding pitching matchup on Friday night.

Jered Weaver is once again putting up magnificent numbers and is a Cy Young contender this year (h/t Zachary Rymer of Bleacher Report). Dempster has a 4.48 ERA since joining the Rangers prior to the trade deadline, but he does have seven wins.

1) Yu Darvish vs. Zack Greinke

Jeff Gross/Getty Images

The Los Angeles Angels are going to have an incredibly difficult road ahead of them when it comes to their postseason chances. After going against Ryan Dempster to begin their series against the Texas Rangers, they face off against YuDarvish on Monday.

YuDarvish has been outstanding in his first year in the majors, and in almost any other season, he would have a good chance at winning the American League Rookie of the Year award.

While Zack Greinke initially struggled after joining the Angels, he has turned things around and now has a 3.51 ERA through 11 starts.